Fluid checking device



oct. Al, 1935. Q 1 BOCK 2,015,837

FLUID CHECKING DEVICE Filed oct. e, 1955 2 sheets-sheet 1 Oct. 1, 1935. 7b BOCK 2,015,837

FLUID CHECKING DEVICE Filed oct. e, 1953 2 sheets-sheet 2 Y Patented Oct. 1, 1935 FLUID cHEoKING DEVICE Charles L. Bock, Chicago, Ill., assigner to Andrew Hoffman, Chicago, Ill.

Application October 6, 1933, Serial No. 692,393

, 11 Claims.

This invention relates to new and improved fluidV checking devices, particularly characterized as double-acting and especially adapted for use in `double-acting door closing and checking de- The invention is herein illustrated as embodied in a door check having in conjunction therewith spring means for closing the door.

It is an object of this invention to provide a double acting cylinder and piston construction' which employs a, shorter cylinder than heretofore has been possible with prior constructions, without sacrificing thefworking or checking stroke of the piston.

" It is a Yfurther object of this invention to pro- 3 vide a double acting cylinder piston construction, the piston of which is formed in two` parts mountby referring to the j` Figure 6`i s a plan` View of the device `shown in ed in overlapping relationship, and provided with racks forengagement with a pair of mutilated gears adapted to impart movement thereto.

It is a further object of this invention to provide in a double-acting piston and cylinder construction, a new and improved mechanical movement as a driving connection between an operating spindle and the two parts of said piston, whereby a new and improved double-acting checking operation results.

These and other objects not specifically enumerated will appear to one skilled in the art as the following description proceeds.

The invention may be more clearly understood accompanying drawings in which:

` Figure 1 is a cross sectional view` in elevation of a concealed overhead double acting door check embodying as a part thereof, the improved piston and cylinder construction constituting this invention;

i p rFigure 2 is a. pian viewoftiie device iuustrated in Figure `1;

Figure 3 is an enlarged planvview` in cross' section of the piston and cylinder construction of this invention,` and f Vliigurc-:dlfis an elevational view in cross section taken on'the line 4-4 of Figure 3 and looking in the direction of the arrows; Y

I Figure 5 is' a similar to Figure 1, showing a concealed floor check for a double acting door embodying theimprovement of the present invention;

Figure 5; A

Figure 7 is an enlarged elevational View in cross section taken on the line ,'I-l of Figure 5 and looking inthe direction ofthe arrows;

Figure 8 is a fragmentary plan view of the spring operating'yoke embodied in the device of Figure 5, and A Y Figure 9 Vis an enlarged perspective view of the adjustable stop device embodied in the construc- 5'- tion shown in Figure 5.

4By referring to the drawings, particularly to Figures 1, 3 and 4, it will be noted that the improvement of this invention is illustrated as embodied ina fluid `checking device or dash pot lo for door checks comprising a cylinder I, having threaded` openings 2 and 3 respectively, at each end thereof. These openings are'closed respectively, by threaded plugs 4 an'd 5. The cylinder is provided with an enlargement 6 on one side 157 thereof having a longitudinal duct or passage "I, which communicates at the intermediate portion of the cylinder with the interiorspaces thereof Y and at its twoends by by-passes 8-9 and I0--I I,

respectively. lThese ducts provide for the reg-20V ulatedescapement of a suitable iiuid such as glycerin, for instance, which is contained Y,in the cylinder and the passage of which is controlled by suitable adjusting screws I2-I3 and I4-I5.

Intermediate the cylinder is an upward standing 25 cylindrical portion I6 which is closed by a cap Il, provided with a central bearing. On the opposite wall of the cylinder, in alignment Vwith the bearing referred to, is abearing I8 adapted to receive ther lower end of shaft I9 which has its upperf end extending through the bearing in the cap I I. Shaft I 9 is provided with two driving gears 20 and 2Irespectively, which have teeth thereon throughout only a portion of their circumference whereby'to provide a set of mutilated gears. It will be noted that the" driving teeth of said gears are arranged on opposite sides so that when one gear is in mesh with its corresponding rack, the other gear is out 4of mesh and vice:- versa. Y

The piston is composed of two parts, 22 and 23,4 having respectively, pistonheads 24 and 25. Each is provided with a rack 26 ,andr21 and a guide head 28-29, respectively, at its opposite end.` The piston parts are` so disposed within the cylinder that for the position of the driving shaft shown in Figure 3, both pistons are in outward positions towards the ends of the cylinder. As the result, movement of theshaft in either direction causes one or the other of the pistons 50 to be picked u p andldrawn toward the center of the cylinder so that, rupon reversing the movement, only that piston which has been thus moved to the central position is brought into ton has been moved to the end of the cylinder a continued movement of the shaft in the same direction subsequently picks up the other piston part and moves it toward the center of the cylinder and upon a reversal of the shaft, causes it to check toward the end of the cylinder in the same manner.

This construction eiects a real and substantial improvement in various applications such as in door checks, because it avoids the travel of the inactive piston While the active piston is moved to accomplish the work of checking. It accordingly allows a much shorter cylinder length than would be necessary for an ordinary dumb bell double headed piston. Furthermore, it allows the mounting of both piston heads in alignment in the same cylinder which makes for a simplified and improved construction.

In the form of the invention shown in Figure l, it will be notedthat the piston construction is mounted in a housing 30, placed'in theA door frame 3'I above the door and is connected for operation 'with the door 'by meansof the slide guide 32, arm'33, spindle 34,and'gears 35 and 36, the latter of which gears is mounted on the spindle I9 of the fluid checking device. The springs for closing the door are brought into operation by means of pins or other suitable connections 3l, carried by the gear 36 which pins act `on'the flexible chains 38 and 39, connected to the springs 4D and 4I, respectively.

The mechanism other than the fluid checking device, constitutes nofpart of the present invention but it is herein for convenience illustrated as being of the same form as that disclosed in Letters Patent No. 1,949,758 of Lewis C. Norton. issued March 6, 1934.Y Y

In the form of the invention illustrated in Figures 5 and 6, it will be noted the iiuid checking device is mounted in a housing 40 which is located in the floor below the door and is'connected. directly thereto by means of an arm 4|, and slide guide 42. The springs 43 and 44, respectively, are connected by means of a yoke 45, carried by the fluid checking spindle I9, and chains 46 and 4l, respectively. These chains are adjustably attached to the spring sleeve 48 by' means of the connections clearly shown in Figure 6. By these conections the springs may be wound up and adjusted, as for tension. In addition to the parts thus described, this checking device embodies a stop elementv 50, which is loosely mounted over the spindle I9, and isfadjusted as to angular position by means of the arm 5l and set screws 52, which bear thereagainst and are threadedly mounted through lugs carried on the cylinder. This stop element is provided with seats 53 adapted to receive pins 54, carried by the end of the chains 46 and 41, so that each will` be seated and come to rest when thespindle I9 is in the neutral position as shown in Figure 6.v *I

It 4will bevobserved that the neutral position can be altered by adjusting the screws 52 and thereby altering the angular position of the stop element 5B. When the shaft I9 swings in either direction, aswhen the door is open, one of the arms of the yoke 45 is caused to pick up its associated jpin 54 and tension the spring connected thereto. During this movement, the other arm Vof the yoke moves away from the seat leaving the pin h54 restingV in the seat 53. For'the-other direction of movement of the door, the reverse action takes place. This provides a satisfactory doublejvacting spring tension While providing a ing to the needs in use, while at the same time, 5

causing the door to be exactly centered with respect to the door sill. The centering of the door in the form of device shown in Figure 2, is accomplished by means of the adjustable lugs 69, mounted on the side of the housing 30, which 10 have their ends placed in cooperating relationship with the lugs 6i carried on the end link of the chain. It will readily appear that the chains will be picked up and seated under reverse movement of the door exactly as described in con- 15 nection with the other modification.

In both cases, the guide slide for operating thedoor is mounted in a suitable slide in the bottom or top edge of the door, as the case may be, and the door is mounted for pivotal move- 20 ment on suitable hings 65 as shown in Figures 1 and 5, respectively. In controlling the dash pot action, two speeds are provided for by means of ducts 8 and 9 for one end of the cylinder and ducts iB and i l, for the opposite end of the cylin- 25 der. By adjusting each of the screws independently one speed can be eiected for the primary or general movement of the door, whereas a finer and more accurate adjustment can be made for controlling the door at the latch. 30

closers as the piston and cylinder device herein 40'v described is useful and desirable for other purposes Where a double checking action is desired. Furthermore, insofar as the claims herein are directed to door closers, they are not to be construed as limited to the particular type of closers 45 here set forth as the invention has utility and advantage in many other types of double acting door checking devices.

I claim:

1. A fluid checking device of the character de- 50'- scribed, comprising a single cylinder and a two part double acting piston mounted for reciprocation in said cylinder, each part comprising a piston head and a rigidly extending gear rack,

said gear racks being disposed between said piston 55'l heads and arranged in overlapping relationship, a pair of mutilated gears in said cylinder mounted for simultaneous rotation and in mesh with said racks, respectively, said mutilated gears being constructed and arranged to move only one of said racks at a time.

2. A uid checking device of the character described, comprising a single cylinder and a two part double acting piston mounted for reciproca- X tion in said cylinder, each part comprising-a piston head and a rigidly extending gear rack, said gear racks being disposed between said piston lheads and arranged in overlapping relationship,

a pair of mutilated gears in said cylinder mounted I for simultaneous rotation in mesh with said racks, respectively, said mutilated gears being constructed and arranged to move only one of said racks at a time, each of said racks having a head on its end opposite the piston head for guiding engagement with the interior of said cylinder. Y 7 5'v 3. A fluid checking device of the character described comprising a cylinder and a two part piston in said cylinder, each part comprising a piston head and a rigidly extending gear rack, said gear racks being arranged in overlapping relationship, means for driving said piston comprising a pair of mutilated gears, one each adapted for meshing engagement with said racks, respectively, the teeth of one gear extending throughout an arc of substantially 180 degrees and the teeth of the other gear being opposite to the teeth of the iirst gear I and extending substantially throughout an arc of 180 degrees.

4. A iiuid checking device of the character described comprising a cylinder and a two part piston in said cylinder, each part comprising a piston head and a rigidly extending gear rack, said gear racks being arranged in overlapping relationship, means for driving said piston comprising a pair of mutilated gears, one each adapted for meshing engagement with said racks,

respectively, the teeth of one gear extending throughout an arc of substantially 180 degrees and the teeth of the other gear being opposite to the teeth of the first gear and extending substantially throughout an arc of 180 degrees, said mutilated gears being mounted on a single shaft.

5. A fluid checking device of the character described comprising a cylinder and a two part piston in said cylinder, each part comprising a piston head and a rigidly extending gear rack, said gear racks being arranged inoVerlapping relationship, means for driving said piston comprising a pair of mutilated gears, Voneeach, adapted for meshing engagement with said racks, respectively, the

teeth of one gear extending throughout an arc of substantially 180 degrees and the teeth of the other gear being opposite to the teeth of the first gear and extending substantially throughout an arc of 180 degrees, said mutilated gears being mounted on a single shaft, and mounted in bearings disposed` centrally of said cylinder.

6. A uid checking device comprising a single cylinder and a two part double acting piston, each piston part comprising a piston head and a rigid extension, said piston parts being mounted for Y reciprocation in said cylinder with their heads of said cylinder, each of said piston heads having a rigidl gear rack extending into the central portion of said cylinder between said piston heads, a shaft in said cylinder having a pair of mutilated gears thereon in mesh respectively with said gear 5 Aheads at a time, said gear racks being arranged in overlapping relationship having their adjacent faces in ,sliding contact.

9. A fluid checking device comprising a single 2 0 `longitudinal cylinder, a pair of oppositely disposed reciprocating piston heads mounted in each Vend of said cylinder, each of said piston heads having a rigid gear rack extending into the central portion of said cylinder between said piston 25 heads, a shaft in said cylinder having a pair of mutilated gears thereon in mesh respectively with said gear racks and adapted to drive only one of said piston heads at a time,` said gear racks being arranged in overlapping relationship having their 30 adjacent faces in sliding contact and each having a portion at its end providing a guide member having sliding contact with the wall of said cylinder.

l0. A fluid checking device comprising a single 35 longitudinal cylinder, .a pair of oppositely disposed reciprocating piston heads mounted in each end of said cylinder, each of said piston heads having a rigid extension Yprojecting into the central portion of said cylinder betweensaid 40 piston heads, a shaft in said cylinder having driving means thereon in driving connection with eachof said extensions respectively.

1l. A fluid checking device comprising a single longitudinal cylinder, a pair of oppositely disposed 45 reciprocating piston heads mounted in each end of said cylinder, each of said piston heads having a rigid extension projecting into the central portion of said cylinder between said piston heads, a shaft in said cylinder having driving means there- 50 on in driving connection with each of said exten sions respectively, said extensions being arranged in overlapping relationship and having their adjacent faces in sliding contact.

CHARLES L. BOCK. 

